Don't Panic

Stephen Hawking explains how to escape a black hole

By Adam Epstein

If you find yourself stuck inside a black hole, Stephen Hawking says not to panic.

Current science suggests that a black hole’s gravity is so strong that absolutely nothing—not even light—can escape once inside. They are cosmic vacuums of terrible, unthinkable power… and there’s about 100 million of them in our galaxy alone, including an enormous one at the center that’s billions of times bigger than the sun. Fun stuff.

But perhaps there is hope after all. Hawking, the most famous physicist in the world, has a new theory about black holes, and when Hawking theorizes, people listen. Much of what we already know about black holes is because of Hawking—in fact, there are even concepts named after him. So it’s no trivial matter when he has a new idea.

Speaking at the KTH Royal Institute of Technology in Stockholm, Hawking argued that information that is sucked into a black hole is not doomed to remain there forever. “There’s a way out,” he said.

For decades, physicists have been perplexed by the question of what happens to the information of particles passing through black holes. Science says it can’t be permanently destroyed, but where does it go? In what state does it exist? Hawking now believes that the information never really enters the black hole to begin with.

“I propose that the information is stored not in the interior of the black hole as one might expect, but on its boundary, the event horizon,” he said.

If you’ve seen Interstellar, you’re familiar with the event horizon—it’s essentially the boundary that delineates the point of no return. Once past it, the black hole has you in its nightmarish forever-embrace.

The particles’ 3D information is translated into a 2D hologram and hangs out in the event horizon. Remember that concept named after Hawking we mentioned? Hawking Radiation—or photons ejected from a black hole due to quantum fluctuations—is what then helps the information escape from the event horizon. The outgoing Hawking particles can, so to speak, pick up the information on its way out of the black hole.

Though the information might have escaped the black hole, it’s not exactly its former self. “The information about ingoing particles is returned, but in a chaotic and useless form,” Hawking said. “For all practical purposes, the information is lost.”

That said, being “lost” outside of a black hole is still probably better than being inside of one. Hawking even suggested that the information could come out in another universe. “The message of this lecture is that black holes ain’t as black as they are painted,” he said. “They are not the eternal prisons they were once thought.”

None of this is to suggest a human being could survive being consumed by a black hole (most scientists believe the intense tidal forces would snap you like a twig before you could say “McConaughey”).

But it’s comforting, perhaps, to know that if you were to get devoured by the universe’s apex predator, the particles that made you you could someday be recovered.